APPLICANT'S ABSTRACT: A five-year study is proposed in response to Program Announcement 94-054, "Strategies to Reduce HIV Sexual Risk in Drug Users." The proposed study is designed to develop, implement, and evaluate a culturally innovative HIV intervention model for 1,110 heterosexual injection drug users (370 non- Hispanics and 740 Mexican- Americans), and 300 sexual partners of Mexican- American IDUs. The study will be conducted in three phases (a formative phase, a model development phase, and an implementation phase) which will target nine Mexican-American barrios in Tucson, Arizona. The specific aims of the study are to: 1) examine and identify contextual factors such as cultural norms, beliefs, and perceptions related to HIV risk and the expression of sexuality among this high risk group of Mexican-American IDUs and their primary or secondary female sexual partners; 2) examine and identify high risk sexual and injection practices that are conducive to HIV transmission; 3) seek to understand the cultural context of gender roles and their relevance to sexual risk reduction; 4) determine the congruence of major theoretical HIV/AIDS behavioral change models with the lifestyle and cultural characteristics of the targeted population; 5) develop a culturally innovative HIV/AIDS sexual risk reduction intervention based on the formative phase of the study; 6) implement a theory-based, culturally innovative HIV/AIDS sexual risk reduction intervention; and, 7) collect process and outcome data to assess the efficacy of the culturally innovative intervention in reducing high risk sexual and injection behaviors. To accomplish these specific aims, the study proposes a three-staged methodology. The first stage, the formative phase, will utilize both qualitative and quantitative approaches to understanding the patterns of HIV risk engagement and potential points of intervention. In-depth qualitative interviews and focus groups will be used to develop core components of the proposed culturally innovative intervention. The second stage, the model development phase, will use the information gathered during the previous phase to develop the culturally innovative intervention. The third stage, the implementation phase, will utilize a quasi-experimental design with randomization of participants to one of two interventions-- the culturally innovative intervention or the universal culturally sensitive intervention. The research design calls for a baseline, 6- month, and 12-month follow-up assessment. The study will also collect key process and outcome information to assess the efficacy of the intervention in changing sexual risk and injection risk behaviors.